Tapeworms live in the intestines of cats, dogs, other animals and humans upon infection. They attach to the lining of the intestine and parasitize their host by feeding on the nutrients in the intestine. Tapeworms are not free-living worms, and before they can infect an animal or human, they have to pass through an intermediate host. The primary intermediate host is the flea. You can prevent a tapeworm infection or re-infection by removing animal feces and getting rid of fleas in your yard.
Adult tapeworms live in the small intestine of their host. The most common tapeworm that infects cats and dogs is Dipylidium caninum. In the intestine, the tapeworm can reach 8 to 12 inches in length. It consists of up to 200 flat, rectangular pieces, called proglottids. As the sections of the tapeworm mature, they develop egg sacs inside. When mature, the proglottids detach and are eliminated in the animal's feces. Freshly eliminated proglottids are white or light pink and wiggle around, but when the pieces dry out, they break open and release the tapeworm eggs. Flea larvae feed on the eggs, which hatch inside the fleas and develop into an immature form of tapeworm. When cats, dogs or other animals ingest infected fleas, the tapeworm grows and matures in their intestines -- completing its lifecycle.
Remove Animal Feces
When a tapeworm-infected dog or other infected animal defecates in the yard, it passes proglottids, the tapeworm sections, in the feces. The tapeworm proglottids are about 1/8 of an inch long and look like cucumber seeds or grains of rice (see Reference 2). The proglottids, which contain tapeworm eggs, cannot infect pets or people directly, because they need to pass through fleas or lice to become infectious. Nevertheless, feces from tapeworm-infected animals can provide a continuous source of new infections, provided fleas are present. To remove animal feces in the yard, bury feces or dispose of them in double bags in the trash.
Treat Flea Infestations
Fleas are crucial for the development of an infectious tapeworm stage. Getting rid of fleas in the yard as well as indoors will prevent tapeworm infections and re-infections. Insect sprays, containing pyrethrin and the insect growth regulator pyriproxyfen, kill adults fleas and stop immature fleas from maturing to a reproducing stage. Growth regulator products used for fleas work for approximately seven months before another application is necessary. To treat your lawn, mix six ounces of 36.8 percent pyrethrin concentrate and four ounces of pyriproxyfen into a 20 gallon hose-end sprayer. This amount will treat 4,000 to 6,000 square feet. Only spray sites in your yard that are likely flea breeding sites, such as areas that pets frequent, moist and shady areas and areas under decks and shrubbery. Sunny areas do not harbor fleas, because the sun desiccates flea larvae. Keep children and pets out of the area until the product has completely dried. To keep the insecticide off your skin, wear gloves, clothing that covers your arms and legs, as well as safety goggles to protect your eyes. Wash your hands immediately after use. Always follow the specific directions of any product you use.
Prevent Tapeworm Infections
Prevent flea infestations and sources of tapeworm infections in your yard by taking a number of measures. Keep your pets flea-free. Mow your grass often so that tall grass does not provide a home for fleas. Trim your shrubbery to let more sunlight in; flea larvae need moisture and prefer shade. Patch openings in your fence to prevent flea-infested or tapeworm-infected wildlife and stray dogs and cats from visiting and defecating in your yard.
Based in Connecticut, Marie-Luise Blue writes a local gardening column and has been published in "Organic Gardening" and "Back Home." Blue has a Ph.D. in biological sciences from the State University of New York at Stony Brook and wrote scientific articles for almost 20 years before starting to write gardening articles in 2004.